On Apr 10, 2006, at 14:52, Matthias Felleisen wrote (quoting Hoare):
> Imagine yourself learning how to run an ocean-going sail-boat.
> Of course, you start with exercises on land. You wear your
> life vest, too. When you're ready, you take the sailboat out
> on the ocean, and to avoid the weight, you leave the life
> vests behind on land. That's what it means to run code with
> contracts [he said "assertions"] turned off.
This is a great image. Something similar happened in rowing. 10-15
years ago, British authorities ruled that coxswains had to wear life
vests. In the U.S., we laughed. U.K. coxswains complained the vests
were too bulky. The market responded with lightweight non-bulky
vests that erased most objections. The new vests work well enough
that rowers too use them now for added safety when the water is
dangerously cold (late winter & early spring), saving lives worldwide.
Geoffrey
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Geoffrey S. Knauth | http://knauth.org/gsk